Folding device for rotary printing machines



oct. 15, 1935. H FRlTZ 2,017,619

FOLDING l*DEVICE FOR ROTARY PRINTING MACHINES Filed Nov. 2, 1954 ,7m/mier:

Patented Oct. .15, 1935 UNITED STATES PATENT OFI-fici?.A l

l FOLDING DEVICE FOR ROTARY PRINTING F MACHINES Application November 2, 1934, Serial No. '151,225 l In Germany January 25, 1934 5Claims.

This invention relates to a folding device intended primarily for use in rotary printing machines for the production of newspapers or similar work printed from an endless web and cut and folded afterwards.

In a known type of such machines there is for this. purpose a. cuttingv and a folding cylinder working together and underneath the same a pair of folding cylinders into and between which .the cut sheets are folded by means `of a folding knife. The folding cylinder is provided with suitable sheet holding means, e. `g, pins which at the moment of cutting seize the running web and take it round by about half a revolution' of the folding cylinder until the front end of the web is cut oi by the length of a sheet. Simultaneously with the folding of the sheet it is released again by the pins.

It is necessary that the sheets should be folded exactly in the middle. The above folding device has however the disadvantage that the exactness of the fold depends on the speed of the machine and that consequently it is-not always uniform.L

AIf for-instance the machine furnishes exactly folded products at slow speed, the fold at higher speed will be inexact, i. e. the end of the copy will project over the other end. The contrary will be the case if the device is made so that the fold is exact at high speed but if the machine then runs at a lower speed.

In order to prevent this it will be necessary that the cam or the like which controls the releasing of the cut sheet at the moment of folding, is-

^ conforming to the speed of the machine-adjusted so that'the pins release the sheet a little earlier at high speed of the machine than atlow speed.y

For this purpose. an adjusting device for the cam for controlling the movement of the pins has been known, by which device the adjusting ,been reached. Nevertheless it cannot be avoided that badly folded copiesxare delivered. f For different reasons, as e. g; for changing the reels, washing the piatesffurther owing to paper breaks etc., the speed of rotary printing machines is frequently changed during the-printing of an edition, such change having to be effected from stoppage upto maximum speed. Besides, the

speed of the machine is not always the (Cl. 27o- 77) i speed, but at times is reduced more or less. Such being the case it will easily be understood that adjusting the fold by hand while the machine is running is not only a troublesome andunpractical but also an unreliable operation. This deficiency is eliminated by the present invention.

According to the invention there is a camv or the like which controls the release of thev cut sheets by means of pins or the like in the folding cylinder at the moment of the folding, such cam ll0 being automatically adjustable according to the speed of the machine.

` For this purpose the cam is shifted automatically .by the action of a centrifugal governor which is eonneeted'with the gennng of the me- 15 chine.

Once the pin controlling cam has been adjusted after setting up the machine, an exact register of the edges of all copies will be ensured at any speed of the machine without the aid or 20 the control of the operator. Any adjustment of. the fold by hand while the machine is running is eliminated.

The accompanying diagrammatic drawing illustrates, by way of example,.a construction ac- 25 revolutioml The small arms l5 -for the move- 35 ment of the needles are arranged on rockshafts 6. The movement of the needles at each gripping point is controlled by a roll arm 1, and a roll 8 coactlng with a cam 9. .At the same moment that the cut sheet is folded, the front end of the same is released by the collecting needles 4. The fold is initiated by'a folding knife I0 which folds `the sheet into andbetween two rotating folding rollers II, cylinder. A

Cam 9 for controlling the movement of they collecting needles' is arranged shiftable on the folding cylinder 2 or rather on the folding cylinder axle I3. Thiscam is, according to the speed of thev machine, way that the collecting needles I release the sheet earlier, ,relatively to the folding operation', at high speed of the machine than at low speed For this purpose the centrifugal governor I4 is provided which is driven by the machine itself et a 5 I2 arranged underneath the folding s ted automatically in such a 50 suitable speed. By this centrifugal governor the lever I6 is moved which is shiftable upon an axle I5 and which at the end that is opposite to the axle I5 is provided with a groove II of a suitable design. A bar I8 which may be shifted in a straight line carries at its one end the roller I9 which is guided by groove I1, whereas a pin 20 or the like which is fastened to the other end of thebar lies in a slot 2| of cam 9. Consequently when changing the speed of the machine, cam 9 is shifted so that the collecting needles release the sheet earlier or later relatively to the folding operation.

Especially in the case of high speed rotaries experience has shown that cam 9 should not be shifted proportionately to the chai-:g2 1g speed o f. the machine. Corresponding to a gwen number of revolutions of the machine, the shifting of cam 9 is preferably effected by means of a curved piece I'I arranged between the centrifugal governor I 4 and cam 9. 'I'he shape of the curved piece may be determined on the basis of observations made in practical service.

The centrifugal governor which may be of any design may also be connected with cam 9 by other suitable rods, links or gearings.

While the invention has been described in its preferredform, it will be understood that numerous changes and variations might be devised for carrying out the invention and it is therefore not to be restricted to purely mechanical controlling means, nor to the 'construction shown and deting cylinder, sheet holdingmeans on the folding cylinder, l:wofolding rollers arranged underneath the folding cylinder, into and between n which rollers the cut sheets are folded, means for releasing the sheets from said holding means including a shiftable cam and means for auto-` matically shifting the cam'in proportion to the speed of the machine to hasten or retard the release of the sheets from the sheet holding means.

2. In a folding apparatus a cutting cylinder, a folding cylinder working together with the cutting cylinder, sheet holding means on the folding cylinder, folding rollers arranged underneath the 5 folding cylinder, into 4and between which rollers the cut sheets are folded, a cam for the movement of the sheet holding means of the folding cylinder and a centrifugal governor driven by the gearing of the machine for automatically shift- 10 ing the cam which moves the sheet holding means of the folding cylinder.

3. In a folding apparatus a cutting cylinder, a folding cylinder working together with the cutting cylinder, sheet holding means on the foldl5 ing cylinder, two folding rollers arranged underneath the folding cylinder, into and between which rollers the cut sheets are folded, means for releasing the sheets from said holding means including a shiftable cam, means for shifting 20 the cam to vary the time of 'release of the sheets by the sheet holding means and a centrifugal governor -for automatically operating the device for shifting the cam.

4. In a folding apparatus a cutting cylinder, a 25 folding cylinder working together with the cutting cylinder, sheet holding means on the folding cylinder, two folding rollers arranged underneath the folding cylinder, into and between whichrollers the cut sheets are folded, a shiftable cam for thelmovement of the sheet holding means of the folding cylinder, a shiftable curved piece by which the cam is shifted and a centrifugal governor for automatically shifting this same curved piece in correspondence with SII the speed of the machine. y 1 l 5. In a folding apparatus, a cutting cylinder,

a folding cylinder coactlng therewith, sheet holding means'on the folding cylinder, folding means to which the sheets are fed from the folding cyl- 40 inder, means for releasing the sheets .from the folding cylinder, and means for automatically varying the time of such release in timed relation to the speed of the machine.

HANNS FRITZ. 45 

